1. Field of the Invention
The present invention relates to an equipment management system for systematically performing data communication and managing a network, such as a management system for supporting component-by-component maintenance services for components that require regular replacement such as photosensitive drums and paper feeding parts of electronic photocopiers, and especially relates to an improvement on the method of managing component lifetimes.
2. Description of the Prior Art
These days, between users of photocopiers and a maintenance company that manages those copiers is often operated a copier management system that mainly utilizes telephone lines. Such a management system enables the maintenance company to collectively manage a large number of copiers in terms of, for example, replacement component procurement, machine condition, copy count, paper-jam history, maintenance data, and others, on a copier-by-copier basis.
Generally, in a copier management system of this type, a communications control device is attached to each of the copiers, and a host computer is installed in the maintenance company. The device is linked to the host computer over a telephone line via communications modems provided at each end. Here, the host computer not only receives from the device all data concerning the copier, including data for calling a serviceperson, but it also sets data on that device; for example, the host computer sets the phone number by which it is accessed, the time at which regular periodical dialing is performed, the copy count permitted under contract, and others, in order to initialize the copier. Based on those settings, the device communicates with the host computer. In this way, all the copiers are managed collectively.
In such a management system, the communications control device is conventionally constructed, for example, as follows. The conventional device is provided with a plurality, e.g. 22, of resettable count fields, and those count fields are each allocated to different major components or units that require replacement as a result of exhaustion or wear. Some of these components or units are interlocked with the total count of the copier, and some are interlocked with other signals. For example, in the case of paper-feed units, each paper-feed unit individually performs paper-feed actions, and the total count is incremented every time such a paper-feed action takes place.
It is possible to set threshold values individually for the counts stored in the above described component-by-component count fields provided in the device, so that, when a threshold value is exceeded, the device generates a report indicating that the corresponding component is being used beyond its lifetime, and transmits the report to the host computer. The host computer regularly checks such reports received from the device, so that, if necessary, a serviceperson visits the site where the copier is installed and performs maintenance work for the copier, including replacement of components listed in such reports.
The threshold values are usually set to, for example, 90% of actual component lifetimes, so that the components can be monitored to be protected against use beyond their lifetimes. Furthermore, when a threshold value for a component is exceeded, it is also possible, in addition to transmitting a warning report to the host computer, to transmit all the component-by-component count data at the same time as such a report is transmitted. Note that the counts in the count fields can be reset individually on an occasion of maintenance of the copier.
However, in the above described conventional system, the 22 count fields are individually compared with their respective threshold values, and, every time one threshold value is exceeded, the host computer needs to be accessed through communication. This means that communication occurs 22 times at most. As a result, such a system not only leads to high communication costs, but also makes monitoring tasks difficult because, during periods between regular checking sessions, the host computer becomes heavily loaded with reports from the device, with its screen filled with a large amount of information.
To solve such problems related to communication costs and others, the device may be so configured that, when a threshold value for one component is exceeded, the device transmits the count data for the other components as well. This allows the counts to be reset every time communication takes place, and accordingly only one communication session is required. However, since the counts for components other than that particular component are also reset, it is not possible to know the conditions after the communication session. Thus, this configuration fails to achieve the original aim.
Moreover, even though these 22 count fields are incremented according to signals from the copier that are interlocked with them, the counts for individual components and the signals from the copier that are available in the conventional system are predetermined. Accordingly, each count field corresponds to a particular component, and is distinguished by a generic name such as "photosensitive drum" and "developer". For example, for a five-deck paper feed section, even though the first to fifth paper feed decks are defined separately, counting cannot be performed on a component-by-component basis within the paper feed section.
As described above, since the count fields are fixed fields that correspond one-to-one to particular components, it is impossible to flexibly cope with cases where, for example, the copier is replaced with a new model which has a different construction. Specifically, in the above described example, it is impossible to separately manage the individual components within the same paper feed section. More specifically, the paper feed section has a different number of decks depending on the model, and therefore, if the paper feed section has less than five decks, one or more fields will be left unused and blank. Moreover, it is impossible to cope with a model that includes a new expendable component to which no count field is allocated.